Nucleus is covered by a membrane called nuclear membrane and contains many components. Major components of nucleus are nucleoplasm, chromatin and nucleolus.
Nuclear Membrane Nuclear membrane is double layered and porous in nature. This allows the nucleoplasm to communicate with the cytoplasm. The outer layer of nuclear membrane is continuous with the membrane of endoplasmic reticulum. The space between the two layers of nuclear membrane is continuous with the lumen of endoplasmic reticulum. Pores of the nuclear membrane are guarded (lined) by protein molecules. Diameter of the pores is about 80 to 100 nm. However, it is decreased to about 7 to 9 nm because of the attachment of protein molecules with the periphery of the pores. Exchange of materials between nucleoplasm and cytoplasm occurs through these pores.
Nucleoplasm
